Condensate Pump

ABSTRACT

A condensate pump for an HVAC system includes a reservoir, a unitary top support plate, and a cover. A pump motor, an impeller pump, a float, and control electronics are mounted on the unitary top support plate. The transition from the cylindrical volute chamber to the tangential output port of the impeller pump has a swept diagonal surface that creates a gradual transition from the cylindrical volute chamber to the tangential output port. The gradual transition minimizes the pulsing. An intake profile with a concave surface extends from the center of the impeller and matches a complementary intake profile extending from the bottom of the reservoir. Vortex inhibiting vanes are molded into the bottom of the reservoir adjacent the central intake port of the impeller pump to break up any induced vortex within the reservoir.

CLAIM OF PRIORITY

This application claims priority from U.S. Provisional Patent Application Ser. No. 60/956,741 filed on Aug. 20, 2007, which is incorporated herein in its entirety.

FIELD OF THE INVENTION

This invention relates to a condensate pump that collects condensate water from the evaporator of an HVAC system and pumps the condensate water to another location for disposal. More specifically, the condensate pump of the present invention includes an improved impeller pump, an improved component mounting assembly, and an improved reservoir attachment mechanism.

BACKGROUND OF THE INVENTION

A condensate pump is used in an HVAC system to collect condensate water from the evaporator of the HVAC system and to pump the condensate water to a remote location for disposal. Particularly, the condensate pump typically comprises a reservoir, an impeller pump for pumping the water out of the reservoir to the remote location, and an electric motor to drive the impeller pump. A float detects the level of condensate water in the reservoir and activates control circuitry to control the operation of the electric motor.

Condensate pumps are often located in extreme environments and are subjected to moisture, heat, and cold. Moreover, condensate pumps are often installed in inaccessible locations where maintenance is difficult, and therefore reliability over many years is necessary. Further, the condensate pump should operate quietly and without excessive buildup of heat from the operation of the electric motor.

SUMMARY OF THE INVENTION

The present invention addresses the issues raised by the installation of a condensate pump in an extreme environment. Particularly, the condensate pump of the present invention is capable of operating reliably in such an extreme environment over an extended period of time. Further, the condensate pump of the present invention is designed to operate quietly and efficiently.

In order to achieve the objects outlined above, the condensate pump of the present invention embodies a number of features that together produce an improved condensate pump. The condensate pump of the present invention includes a reservoir and a unitary top support plate, which forms the backbone of the condensate pump. The major components of the condensate pump are mounted to the unitary top support plate. In order to mount the condensate pump components, the unitary top support plate has an impeller pump support structure, a pump motor support structure, a cover support structure, a control circuitry support structure, and a float assembly support structure. A pump motor, a motor cover, an impeller pump, a float assembly, and control circuitry are mounted on the unitary top support plate by means of the respective support structures.

With respect to quiet operation, the pump motor is mounted by means of rubber bushings to the unitary top support plate to isolate the vibrations of the motor and heat generated by the motor from the unitary top support plate. Further, the unitary top support plate is tightly mounted to the top of the reservoir by means of a snap connection so that the unitary top support plate, with its mounted components cannot vibrate on top of the reservoir.

Quiet operation is also enhanced by the design of the cylindrical volute chamber of the impeller pump. Particularly, the transition from the cylindrical volute chamber to the tangential output port of the impeller pump has a swept diagonal surface that creates a gradual transition from the cylindrical volute chamber to the tangential output port. The gradual transition minimizes the pulsing that occurs each time the water between successive blades of the impeller rushes through the output port of the volute chamber. The reduction of pulsing by the smooth transition to the tangential output port increases efficiency and reduces noise of the impeller pump.

In addition, in order to promote a constant flow of water into the central intake port of the volute chamber of the impeller pump, a reservoir intake profile with a concave surface and vortex inhibiting vanes are molded into the bottom of the reservoir adjacent the central intake port of the impeller pump. The vortex inhibiting vanes break up any vortex within the reservoir induced by the action of the impeller pump, and the reservoir intake profile directs the water upward in a smooth transition as it flows toward the central intake port of the impeller pump. In addition, the impeller has a matching impeller intake profile with a concave surface centered on the impeller and extending toward the reservoir intake profile to complete the flow transition of the water into the central intake port. The intake profiles and the vortex inhibiting vanes help assure a constant flow of water into the central intake port of the impeller pump thereby minimizing the intake of air by the impeller pump. Minimizing the intake of air by the impeller pump increases the efficiency of the impeller pump and reduces noise resulting from the intake of air.

Further objects, features and advantages will become apparent upon consideration of the following detailed description of the invention when taken in conjunction with the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of the condensate pump in accordance with the present invention.

FIG. 2 is a front elevation view of the condensate pump in accordance with present invention.

FIG. 3 is a front elevation view of the condensate pump (with the reservoir and cover cut away) in accordance with the present invention.

FIG. 4 is a front elevation view of the condensate pump (with the reservoir and cover removed) in accordance with the present invention.

FIG. 5 is a back elevation view of the condensate pump (with the reservoir and cover cut away) in accordance with the present invention.

FIG. 6 is a back elevation in view of the condensate pump (with the reservoir and cover removed) in accordance with the present invention.

FIG. 7 is a top perspective view of the condensate pump (with the cover removed) in accordance with the present invention.

FIG. 8 is a bottom perspective view of the condensate pump (with the reservoir and cover removed) in accordance with the present invention.

FIG. 9 is a detailed top perspective view of the attachment mechanism between the reservoir and the unitary top support plate of the condensate pump in accordance with the present invention.

FIG. 10 is an exploded detailed side perspective view of the snap connection between the reservoir and the unitary top support plate of the condensate pump in accordance with the present invention.

FIG. 11 is an exploded end perspective view of the condensate pump in accordance with the present invention.

FIG. 12 is side elevation view of the impeller pump of the condensate pump in accordance with the present invention.

FIG. 13 is a bottom plan view of the impeller pump of the condensate pump in accordance with the present invention.

FIG. 14 is a bottom plan view of the impeller pump (with its bottom cover removed) of the condensate pump in accordance with the present invention.

FIG. 15 is a top plan view of the impeller pump of the condensate pump in accordance with the present invention.

FIG. 16 is a top plan view of the impeller pump (with its top cover removed) of the condensate pump in accordance with the present invention.

FIG. 17 is an end elevation view of the condensate pump in accordance with the present invention.

FIG. 18 is a bottom perspective view of the impeller pump (with its bottom cover removed) of the condensate pump in accordance with the present invention.

FIG. 19 is a top perspective view of the impeller pump (with its top cover removed) of the condensate pump in accordance with the present invention.

FIG. 20 is a front perspective view of an alternative low profile embodiment of a condensate pump in accordance with the present invention.

FIG. 21 is a front elevation view of the low profile condensate pump (with the reservoir and cover cut away) in accordance with the present invention.

FIG. 22 is a front elevation view of the low profile condensate pump (with the reservoir and cover removed) in accordance with the present invention.

FIG. 23 is a cross-section view of the impeller pump of the low profile condensate pump in accordance with the present invention.

FIG. 24 is a top plan view of the bottom panel of the reservoir of the low profile condensate pump in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning to FIG. 1-8 and 11, a condensate pump 10 in accordance with the present invention comprises a reservoir 12 and a unitary top support plate 14. The reservoir 12 comprises a water tight container with an open top defined by a periphery 28 (FIG. 11). In one embodiment the reservoir comprises a front panel 16, a back panel 18, a left side panel 20, a right side panel 22, and a bottom panel 24. The reservoir may be of any geometric shape. The reservoir 12 has rubber support legs 26 located on the four corners of the bottom panel 24. The unitary top support plate 14 has a flange 30 (FIGS. 4, 6, 8, and 11) around its periphery which engages the periphery 28 of the reservoir 12. In addition, hanger brackets 32 are mounted to the reservoir on the back panel 18. The hanger brackets 32 are used to mount the reservoir 12, on a wall or other elevated support in order to make later access to the condensate pump 10 in some cases easier. The reservoir 12 further has a trough 34 molded into the bottom panel 24 for directing water remaining in the reservoir to the low point in the reservoir.

As shown in FIGS. 1, 3, 5, 7, and 11 the unitary top support plate 14 rests on the periphery 28 of the reservoir 12. A condensate water outlet connector 72 is mounted on one end of the unitary top support plate 14. The unitary top support plate 14 also has inlet openings 38 in the four corners of the unitary top support plate 14 (FIG. 1). Plugs 40 cover the inlet openings 38 that are not in use. As shown in FIGS. 3-8, the unitary top support plate 14 includes impeller pump support structure comprising five downwardly extending pump support legs 36 (FIGS. 4 and 6), a cover support structure comprising four upwardly extending cover support legs 44 (FIG. 7), a pump motor support structure comprising plate segment 92 (FIGS. 7 and 8), a control circuitry support structure comprising plate segment 94 (FIG. 7), and a float assembly support structure comprising plate segment 96 (FIG. 7).

As shown in the FIGS. 4, 7, and 8, an electric pump motor 50 is mounted on plate segment 92 of the unitary top support plate 14 by means of rubber motor mount bushings 84, which isolate vibration and heat generated by the pump motor 50 from the unitary top support plate 14. As shown in FIGS. 3-6, an impeller pump 62 having mounting legs 74 is connected to the unitary top support plate 14 by connecting the impeller pump mounting legs 74 to the downwardly extending support legs 36 of the unitary top support plate 14. A driveshaft 68 extends between the pump motor 50 and the impeller pump 62.

Motor control circuitry 54 and a float assembly 48 are mounted on the unitary top support plate 14 on plate segments 94 and 96 respectively (FIG. 7). The motor control circuitry 54 and the float assembly 48 are operatively connected to each other. The float assembly 48 monitors the level of condensate water in the reservoir 12, and in response to movement of the float assembly 48, the motor control circuitry 54 starts and stops the pump motor 50. The operation of the motor control circuitry 54 and the float assembly 48 is described in greater detail in commonly owned U.S. patent application Ser. No. 11/277,445, filed Mar. 24, 2006, United States Patent Application Publication No. 20070224050, Sep. 27, 2007, which is incorporated herein by reference.

With reference to FIGS. 3-6, a biostat tablet drawer 42 is slidably supported by the unitary top support plate 14. The biostat tablet drawer 42 holds biostat tablets which are introduced into the condensate water to inhibit the growth of algae and other unwanted biological materials. The description and operation of the biostat tablet drawer 42 is described in greater detail in commonly owned U.S. patent application Ser. No. 11/277,445, filed Mar. 24, 2006, United States Patent Application Publication No. 20070224050, Sep. 27, 2007, which is incorporated herein by reference.

The unitary top support plate 14 supports all of the major components, the pump motor 50, the impeller pump 62, the motor control circuitry 54, the float assembly 48, the biostat tablet drawer 42, and the water outlet connector 72. Consequently, the unitary top support plate 42 provides the backbone for the condensate pump 10. By mounting the major components of the condensate pump to the unitary top support plate 14, the opportunities for vibration or damage to the major components are reduced. The assembly is then completed by attaching the cover 46 to the unitary top support plate 14 by means of four cover screws 47 through the cover 46 into the cover support legs 44 (FIG. 3 and 5) and by attaching the reservoir 12 to the unitary top support plate 14 by means of a snap connection 52 described in greater detail below. Thus assembled, the components of the condensate pump are firmly connected together to further reduce the opportunities for rattle due to vibration caused by the operation of the electric pump motor 50 and the impeller pump 62.

As illustrated in FIGS. 9-11, the snap connection 52 between the unitary top support plate 14 and the reservoir 12 ensures a tight connection between the unitary top support plate 14 and the reservoir 12. The snap connection 52 comprises guide projections 86 on the front panel 16 and the back panel 18 of the reservoir 12, hooking tabs 88 extending from the flange 30 of the unitary top support plate 14, and keeper openings 90 in the front panel 16 and the back panel 18 of the reservoir 12 (FIG. 11). In order to connect to the unitary top support plate 14 to the reservoir 12, the unitary top support plate 14 is lowered on to the periphery 28 of the reservoir 12. As the hooking tabs 88 engage the front panel 16 and the back panel 18 of the reservoir 12, the front panel 16 and the back panel 18 are forced outwardly by the camming action of the hooking tabs 88. Once the unitary top support plate 14 has been seated onto the periphery 28 of the reservoir 12, the hooking tabs 88 engage the keeper openings 90 in the front panel 16 and the back panel 18 of the reservoir 12 to hold the unitary top support plate 14 onto the periphery 28 of the reservoir 12. The guide projections 86 facilitate the positioning of the unitary top support plate 14 onto the periphery 28 of the reservoir 12. Further, the guide projections 86 are used to pry the front panel 16 and the back panel 18 of the reservoir 12 outwardly in order to later disengage the hooking tabs 88 from the keeper openings 90 in order to remove the unitary top support plate 14 from the reservoir 12.

Turning to FIGS. 12-19, the impeller pump 62 has a cylindrical volute chamber 56 with an impeller 64 having impeller blades 66 mounted for rotation within. The volute chamber 56 is cylindrical in shape with a central intake port 60 and a tangential output port 58. The tangential output port 58 is connected to outlet tube 70, and the outlet tube 70 is connected to the water outlet connector 72 (FIGS. 4 and 8). The impeller 64 is connected to impeller driveshaft 68 and is driven by the electric pump motor 50 (FIG. 4). In operation, the impeller 64 draws condensate water from the reservoir 12 into the central intake port 60. The impeller 64 then forces the condensate water out through tangential output port 68, through outlet tube 70, and through outlet connector 72.

In order to reduce noise of the impeller pump 62, the tangential output port 58 has swept diagonal surfaces 76 (FIGS. 14, 16, 17, 18, and 19), which are beveled in order to provide a smooth and elongated transition from the radial motion of the water between each of the impeller blades 66 to the tangential direction of the tangential output port 58. Absent the smooth and elongated transition created by the swept diagonal surfaces 76, the water, in a conventional impeller pump, is forced to change immediately from a radial direction to a tangential direction causing a pronounced pounding action as each impeller blades 66 passes by the tangential output port 58. By smoothing and elongating the transition, the water gradually changes direction from radial to tangential thereby resulting in far less pump noise.

FIGS. 20-24 illustrate a condensate pump 110 that is virtually identical to the condensate pump 10 previously described except for the height of the reservoir 112. The reference numerals in FIGS. 20-24 are the same for the same parts in FIGS. 1-19 except that the numeral 1 has been placed before each reference numeral in FIGS. 20-24.

Because of the reduced height of the reservoir 112, the condensate water entering the reservoir 112 through inlet openings 138 moves directly to the central intake port 160 (FIG. 23) of the impeller pump 162. Further, only a small amount of condensate water remains in the bottom of the reservoir 112 during operation of the impeller pump 162. Consequently, the rotation of the impeller 164 in the impeller pump 162 induces a vortex flow of condensate water in the reservoir 112 below the central intake port 160 of the impeller pump 162. Such a vortex flow of condensate water in the reservoir 112 tends to create an air pocket (like the eye of a hurricane) just below the central intake port 160 causing the impeller 164 to draw air through the central intake port 160 into the volute chamber 156. Drawing air into the volute chamber 156, not only reduces the efficiency of the impeller pump 162, but also creates additional noise as the air creates turbulence inside the volute chamber 156. In order to reduce the intake of air through the central intake port 160 of the volute chamber 156, the present invention employs a set of vortex inhibiting vanes 182 molded into the bottom panel 124 of the reservoir 112, an impeller intake profile 178 extending from the center of the impeller 164, and a reservoir intake profile 180 molded into the bottom panel 124 of the reservoir 112 and extending toward the impeller intake profile 178 (FIGS. 23 and 24). In operation, the vortex inhibiting vanes 182 are configured so that the induced vortex circulation within the reservoir 112 is broken up by the vortex inhibiting vanes 182, and the water is directed in a laminar flow toward the central intake port 160. Further, the reservoir intake profile 180 and the matching impeller intake profile 178 provide a smooth transition profile from horizontally flow of the water moving toward the central intake port 160, to a vertical flow of the water into the impeller 164, and finally to a horizontal flow between the impeller blades 166 of the impeller 164. The smooth transition provided by the reservoir intake profile 180 and the matching impeller intake profile 178 reduces turbulence and therefore increases the efficiency of the pump and reduces the intake of air.

While this invention has been described with reference to preferred embodiments thereof, it is to be understood that variations and modifications can be affected within the spirit and scope of the invention as described herein and as described in the appended claims. 

1. A condensate pump for collecting condensate water and pumping the condensate water to a remote location comprising: a. a reservoir having an open top and a bottom panel; b. a unitary top support plate fixed on the open top of the reservoir and comprising: i. an impeller pump support structure extending into the reservoir; ii. a motor support structure on the unitary top support plate outside of the reservoir; iii. cover support structure on the unitary top support plate outside of the reservoir; iv. a control circuitry support structure on the unitary top support plate outside of the reservoir; and v. a float assembly support structure on the unitary top support plate; c. an impeller pump mounted to the impeller pump support structure of the unitary top support plate and having a cylindrical volute chamber, with an intake port, an output port, and an impeller mounted for rotation within the volute chamber; d. a motor mounted to the motor support structure of the unitary top support plate and connected to the impeller pump for driving the impeller of the impeller pump; e. a float assembly mounted to the float assembly support structure of the unitary top support plate for determining the level of water in the reservoir; f. control circuitry mounted to the control circuitry support structure of the unitary top support plate and operatively connected to the float assembly for controlling the operation of the motor based on the level of the water in the reservoir; and g. a cover mounted to the cover support structure of the unitary top support plate for covering the motor and the control circuit.
 2. The condensate pump of claim 1, wherein the unitary top support plate is fastened to the top of the reservoir by a snap connection so that the unitary top support plate snaps onto the top of the reservoir.
 3. The condensate pump of claim 1, wherein the output port of the volute chamber is oriented tangentially to the cylindrical volute chamber and wherein a transition region between the cylindrical volute chamber and the output port has a swept diagonal surface for extending the transition region.
 4. The condensate pump of claim 1, wherein the impeller has an intake profile with a concave surface extending from the center of the impeller toward the intake port of the volute chamber, the reservoir has an intake profile with a concave surface that extends from the bottom panel of the reservoir toward the intake port of the volute chamber and that aligns with the impeller intake profile, and a set of vortex inhibiting vanes extending upward from the bottom panel of the reservoir to break up any induced vortex within the condensate water in the reservoir.
 5. A condensate pump for collecting condensate water and pumping the condensate water to a remote location comprising: a. a reservoir having an open top; b. a unitary top support plate fixed on the open top of the reservoir and comprising: i. an impeller pump support structure extending into the reservoir; ii. a motor support structure on the unitary top support plate outside of the reservoir; c. an impeller pump mounted to the impeller pump support structure of the unitary top support plate and having a cylindrical volute chamber, with an intake port, an output port, and an impeller mounted for rotation within the volute chamber; and d. a motor mounted to the motor support structure of the unitary top support plate and connected to the impeller pump for driving the impeller of the impeller pump.
 6. The condensate pump of claim 5, wherein the unitary top support plate is fastened to the top of the reservoir by a snap connection so that the unitary top support plate snaps onto the top of the reservoir.
 7. A condensate pump for collecting condensate water and pumping the condensate water to a remote location comprising: a. a reservoir for collecting condensate water and having a bottom panel; b. a motor driven impeller pump disposed within the reservoir and having a cylindrical volute chamber, with an intake port, an output port, and an impeller mounted for rotation within the volute chamber, wherein the impeller has an intake profile with a concave surface extending from the center of the impeller toward the intake port of the volute chamber, the reservoir has an intake profile with a concave surface that extends from the bottom panel of the reservoir toward the intake port of the volute chamber and that aligns with the impeller intake profile, and a set of vortex inhibiting vanes extending upward from the bottom panel of the reservoir to break up any induced vortex within the condensate water in the reservoir.
 8. The condensate pump of claim 7, wherein the output port of the volute chamber is oriented tangentially to the cylindrical volute chamber and wherein a transition region between the cylindrical volute chamber and the output port has a swept diagonal surface for extending the transition region.
 9. An impeller pump for a condensate pump comprising a cylindrical volute chamber, with an intake port, an output port, and an impeller mounted for rotation within the volute chamber, wherein the output port of the volute chamber is oriented tangentially to the cylindrical volute chamber and wherein a transition region between the cylindrical volute chamber and the output port has a swept diagonal surface for extending the transition region. 